Apiosporaceae, Xylariales, Sordariomycetes
Basionimo
Arthrinium curvatum var. Minus

DESCRIPTION
Asexual form Colonies are compact, rounded, pointed, black, 80-320 µm in diameter Micelio hyaline to pale brown cells, hyphae 2-7 µm in diameter. Conidiophore stem cell are spherical to lageniform, hyaline with brown pigments and measure 4-)5-7(-8) × (4-)5-6(-7) µm. Conidiophores cylindrical unbranched, straight or flexuous, smooth-walled, hyaline with a brown transverse septum, measuring 30-100 × 2-4 µm. Conidiogenous cells cylindrical 1–1.5 × 1–1.5 µm. Conidia grow along the sides of the conidiophores, curved, rounded at the apices, brown with a germinating hyaline band and a visible scar, (8-)9-10(-11) long in frontal view, (5-)6-7(-8) in lateral view. Sterile cells rounded, paler than the conidia. Crop characteristics flat colonies spreading on the medium, with aerial mycelium growing moderately.
Sexual form in this study has not been seen, it is described by Gutner (1927) and Ellis (1951) as Pseudoguignardia scirpi only seen in pure culture.
NOTES
Arthrinium minus can be confused with Arthrinium curvatum var. curvatum, the conidia of both collections are morphologically the same with the only difference in size A. minus (8-)9-10(-11) × (5-)6-7(-8) µm, whereas A. curvatum var. curvatum 11–15 × 6–8 µm. Ellis (1951) erigió Artrhinium curvatum var. minus as a variety of Arthrinium curvatum and comments that there is no doubt that Artrhinium curvatum var. minus is very close to Arthrinium curvatum and consider that Artrhinium curvatum var. minus is a variety with smaller spores of that species. Minter & Cannon (2018) promoted this variety to Ar. minus species rank due to the difference in size of the conidia of the two varieties which do not overlap. In previous studies specimens of both varieties (AG191036 and AP25418) showed no significant differences in any of the three genetic markers tested (ITS, LSU and tub2) and are therefore considered to be the same species, until genetic evidence to the contrary is found.

 

A Colony on the host; B conidiophore stem cell; C-D Conidiophore stem cell and conidiophore carrying conidia; E-F Curved conidia; G Cologne in MEA 2%; Scale A 200 µm¸B-F 5 µm

HOSPERS
Calamagrostis sp, Carex hirta, C. pendula, C. riparia. Juncus conglomeratus, Scyrpus sylvaticusS. tabernaemonti

DISTRIBUTION
Germany, Austria, Denmark, United States, Finland; France, UK
BIBLIOGRAPHY
Angel Pintos, Pablo Alvarado. Phylogenetic delimitation of Apiospora and Arthrinium. Fungal Systematics and Evolution. 7. 197-221.
Ellis MB (1963). Dematiaceous Hyphomycetes. IV. Mycological Papers 87: 1–42.
Ellis MB (1965). Dematiaceous Hyphomycetes. VI. Mycological Papers 103: 1–46.
Ellis MB (1971). Dematiaceous Hyphomycetes. Commonwealth Mycological Institute, Kew.
Ellis MB (1976). More Dematiaceous Hyphomycetes. Commonwealth Mycological Institute, Kew.
Ellis EA, Ellis JP (1951). British marsh and fen fungi. II. Transactions of the British Mycological Society 34: 497–514.
Gutner LS (1927). History of the development of Camptoum curvatum Link). Materials on Mycology and Phytopathology 6: 301–313. [in Russian]
Minter DW, Cannon PF (2018). IMI descriptions of Fungi and Bacteria 216, sheets 2151–2160. CABI, Wallingford, UK
Pintos A, Alvarado P, Planas J, et al. (2019). Six new species of Arthrinium from Europe and notes about A. caricicola and other species found in Carex spp. hosts. MycoKeys 49: 15–48.

 

Arthrinium Minus fungus